1. Field of the Invention
The invention is directed to a method, a device and a software product for the medical image processing of datasets of a three-dimensional character acquired from medical examination procedures, of the type wherein a separation of the data of relevant anatomical structures as well as of other structures is undertaken proceeding from data in the form of volume element, and a spatial presentation of at least one structure of interest ensues.
2. Description of the Prior Art
The human ability to conceptualize quickly reaches it limits in the spatial interpretation of the information from X-ray exposures or from tomograms as acquired with modern tomographic methods. Modern methods of medical image processing therefore convert the information of a three-dimensional character acquired in medical examinations into spatial impressions of the inside of the body. In general, however, it is not adequate to merely convey a spatial impression of the displayed body region to the medical practitioner. For preparing a reliable diagnosis or for planning a therapeutic measure or a surgical intervention, however, the medical practitioner needs a reduction of the displayed data to what is essential to the practitioner. In other words, the subject of the practitioner's interest must clearly contrast with the environment having only secondary informational content. A number of methods were developed for this purpose that enable an allocation of individual measure values to relevant anatomical structures such as, for example, nerves or fat tissue, bones or tissue equivalent to muscle, as well as to non-anatomical structures such as, for example, foreign bodies. These methods are referred to as segmenting and form the pre-condition allowing a medical practitioner to view, for example, the bone structure of a patient at the picture screen isolated from other tissues.
For planning a surgical intervention, for example after an accident resulting in a complicated fracture, however, this form of presentation of the examination results is often inadequate since although it reflects the actual condition of the structure of interest it does not allow a manipulation of the data with respect to measures to be undertaken; the individual subjects within each and every structure remain fixed in their geometrical arrangement relative to one another in known segmenting methods. The preparation for an intervention to treat a complex multiple fracture therefore requires an enormous mental effort on the part of the orthopedist since he or she cannot verify the allocation of the various fracture surfaces and thus bone fragments to one another at the picture screen.
“Fast Visualization, Manipulation, and Analysis of Binary Volumetric Objects”, IEEE Computer Graphics and Applications, November 1991, pages 53-62, proposes a method for splitting an anatomical structure into two components along a plane to be arbitrarily defined. The separated components can be repositioned in space independently of the original structure.
In “Simulating Motion of Anatomical Objects with Volume-Based 3D-Visualization”, R. A. Robb (Editor): Visualization in Biomedical Computing, Proc. SPIE 2359, 1994, pages 291-300, B. Plesser, U. Thiede and K. H. Höhne propose the division of an anatomical subject into partial subjects that can be subsequently converted into a new spatial arrangement.